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A potassium test checks how much potassium is in your blood or urine. Potassium helps keep the body's water and electrolytes in balance. It is also important in how nerves, heart, and muscles work.
Potassium levels can be tested with a blood test or a urine test. Urine potassium can be checked in a single urine sample. But it is more often measured in a 24-hour urine sample. Your doctor will decide if a urine or blood sample is needed.
A blood or urine test for potassium may be done to:
A health professional uses a needle to take a blood sample, usually from the arm.
A urine test can be done using a single urine sample or urine collected over 24 hours. A single urine sample may be taken at a health professional's office or at home. A 24-hour sample is done at home.
If the container has a lid, remove the lid and set it down with the inner surface up.
After the urine has flowed for several seconds, place the collection container in the stream. Collect about 60 mL (2 fl oz) of this "midstream" urine without stopping the flow. Don't touch the rim of the container to your genital area.
You collect your urine for a period of time, such as over 4 or 24 hours. Your doctor will give you a large container that holds about 1 gallon. You will use the container to collect your urine.
But don't save this urine. Write down the time you began.
Each time you urinate during this time period, collect your urine in a small, clean container. Then pour the urine into the large container. Don't touch the inside of either container with your fingers.
Add this urine to the large container. Then write down the time.
A blood test or one-time urine collection will probably take a few minutes. Or you may collect your urine over a period of 24 hours.
After a blood test:
After a urine test, you will need to return the urine sample to the lab or the doctor's office.
Follow-up care is a key part of your treatment and safety. Be sure to make and go to all appointments, and call your doctor or nurse call line if you are having problems. It's also a good idea to keep a list of the medicines you take. Ask your doctor when you can expect to have your test results.
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Adaptation Date: 3/1/2022
Adapted By: Alberta Health Services
Adaptation Reviewed By: Alberta Health Services
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